The R-type lectin EW29, isolated from the earthwormLumbricus terrestris, consists of two homologous domains (14 500 Da) showing 27% identity with each other. The C-terminal domain (Ch; C-half) of EW29 (EW29Ch) has two sugar-binding sites in subdomainsaandc, and the protein uses these sugar-binding sites for its function as a single-domain-type hemagglu-tinin.